Weiß jemand warum das hier nicht funktioniert

Als Fehlermeldung kommt: "Either there is no default mail client or the default mail client cannot fulfill the messaging request.
Please run microsoft outlook and set it as the default mail client."


<code>
Dim MAPIEng As New MapiEngine
Dim mf As MapiFile
Dim mr(0) As MapiRecip
Dim session As Long
Dim mm As MAPIMessage
Dim file() As MapiFile

mr(0).Address = "lisp@someemailadresssomewhere.com.au"
mr(0).Name = "Lisp"
mr(0).EIDSize = 3
mr(0).EntryID = 100
mr(0).Reserved = 0

mm.Reserved = 0
mm.MessageType = ""
mm.Flags = 100
mm.Subject = "This is the subject"
mm.FileCount = 0
mm.NoteText = "This is Note Text"
mm.RecipCount = 1

MAPIEng.LogOn 0, "myemailboxname", "myemailboxpassword", 1, 0, session

'Blows Up Here
MsgBox MAPIEng.SendMail(session, 0, mm, mr, file, 0, 0)

MAPIEng.LogOff session, 0, 1, 0


</code>

Klappt es denn, wen Outlook Express gestartet wurde?